Liquid cooler control



Noy. 15, 193 8. D. H. DCLISQNi 2,136,813

" LIQUID COOLER CONTROL Filed Sept. 12, 1955 III A I 'I INVENTOR.

Ev! BY A TTORNEY.

. refrigeration in the cooling coil.

Patented Nov. 15, 1938 UNITED STATES" PATENT OFFICE LIQUID COOLERCONTROL Dewey H. Dolison, Mount Vernon, Ohio Application September 12,1935 Serial No. 40.238

' 10 Claims.

serve drinks cold occasionally or continuously.

Up to the present, difficulty has been experienced in such systems inobtaining such flexibility of performance. If the control is set tomaintain a steady cold flow of liquid, then at light loads there is aptto be serious frostbacks and even freezing of the beverage. On the otherhand if the control is. set for light loads, a heavy continuous flow ofbeverage will result in such a severe overload as to prevent properrefrigeration. Reliance is placed upon the cessation of beverage flowbetween successive glasses to obtain proper But it frequently happensthat a large container of beverage is drawn or even successive glasseswithout any interruption'to the flow. In such a case, the difficultiesmentioned above militate against satisfactory performance of a directexpansion system.

An object of this invention is to devise a liquid cooler control for adirect expansion system which will obviate the above difficulties andwill permit the cooling coil to supply a continuous fiow or anoccasional dribble of beverage properly refrigerated.

s A further object is to devise a liquid cooler coil and control whichwill be flexible enough to function satisfactorily from no load to fullload continuous operation in a direct expansion system.

An additional object is to devise a liquid cooler and control which willbe simple, cheap, positive in operation and capable of use withdifierent sizes of installations.

An additional object'is to devise a liquid cooler control which isresponsive to one or more beverage temperatures\ and to supply as muchrefrigeration as the load demands.

Other and additional objects will become apparent as the descriptionproceeds.

Referring to the drawing, I

Fig. 1 shows a complete liquid cooler system with my control appliedthereto.

,Figs. 2 to 5 inclusive show modified forms of liquid cooler coils andcontrol.

Referring to Fig. 1, an electric motor is connected by a belt 2 to acompressor Compressed refrigerant isdelivered through pipe 4 andcondensed in a receiver 5. Liquefied refrigerant is delivered by a pipe6 from receiver 5 tain a suitable pressure in the cooler coil.

to a control valve 1 to be later described .in detail. Valve 1 isprovided with an outlet 8 which is adapted to feed liquefied refrigerantthrough a pipe 9 to a liquid cooling conduit or coil I0.

Cooling conduit or c'oil l0 comprises a plurality of nested conduitssuch as an inner pipe H adapted to have any beverage therein and asurrounding telescoped. pipe l2 adapted to contain the refrigerant.Supply. pipe 9 leads to a suitable fitting l5 at one endof the conduitor coil l0 permitting refrigerant to flow into outer pipe l2 andpermitting beverage pipe I I to extend beyond coil l0. .Coil l0is-extended for any suitable length and may be coiled, as shown, orstraight or disposed in any desirable manner. It may for example be theconnecting pipe between beer kegs in a cellar and faucets in a barfixture. The other end of coil l0 terminates in a fitting l6 similar tol5. From fitting 16 a pipe I! conducts the volatilized refrigerant to aback pressure valve [8 and thence by suction line l9 back to compressor3. Valve [8 functions as a valve to main- Such pressure would besubstantially equivalent to that at which the particular refrigerantemployed in the system boils when the temperature thereof is about thatto which it is desired to cool the beverage in pipe II.

The entire refrigerating system is provided with the customary lowpressure control comprising a pipe 20 leading from suction line l9 to apressure control switch 2| set to operate between two pressure limits.Inasmuch as such control systems are old, no further description isnecessary. When enough, refrigerant in the entire system has volatilizedto raise the pressure in suction line I9 to the critical value, motor Iis switched in and the compressor is driven. Finally when suflicientrefrigerant has been transferred from the suction line to the receiverand liquefied to reduce the pressure in suction line I9 to the criticalvalue, then the motor stops. This control however is supervisory onlyand does not function to control the amount of refrigeration applied tothe beverage. This control is merely to insure a reservoir of liquefiedrefrigerant upon which the cooling coil and its own control can operate.

Itwill, be noted that the beverage in pipe ll comes in at fitting l6 andits flow is counter to that of the refrigerant through the coolingconbulb or receptacle is a sleeve over inner pipe H and within outerpipe II. This sleeve has its ends 25 and 21 crimped down to pipe II andsuitably soldered thereto to form a gas tight chamber. A pipe orcapillary tube 28 leads from bulb 25 to valve 1 through cover plate 30.This cover plate with a flexible diaphragm 3| forms an expansiblechamber 32 in gaseous communication with bulb 25. A suitable expansiblefluid such as methyl chloride may be disposed within bulb 25.

Cover plate 30 is attached to valve body 33. Within valve body 33 is 'apush rod 34 attached to a head 35 disposed in proximity to diaphragm 3|.The bottom of rod 34 rests upon a ball valve 35 pressed upwardly againstits seat 31 by a spring 38 and cup-shaped retainer 33. Pipe 5communicates with chamber 40 within the lower part 4| of the valve bodywhile pipe 5 communicates with the outlet portion of valve 1. Uponexpansion of gas within bulb 25 and chamber 32, diaphragm 3! is sprungdownwardly to force ball 35 away from its seat and open valve 'I.Befrigerant in liquid. form and under pressure is thereupon forced intocooler coil l0. While I have described valve 1 in detail, it isunderstood of course that any other suitable valve mechanism may beused.

Assuming receiver 5 has suflicient refrigerant in liquid form therein,coil or conduit I0 will operate as follows: Under no load conditions.the column of beverage will be at a temperature of approximately 45 F.for example. Under these conditions, conduit i5 willhave a portionthereof .filled with liquefled refrigerant to a point near thereceptacle or bulb 25. If a glass of beverage is drawn, the entirebeverage liquid column will advance in inner pipe ll downward as seen inFig. 1. Some warm beverage will come into contact with bulb 25 and causethe pressure therein to increase. This will result in valve I openingand permit liquid refrigerant to rush into outer pipe l2. Liquidrefrigerant will advance to contact the receptacle or bulb 25 which willbe chilled and valve 1 closed. The liquid refrigerant will graduallyrecede or be forced back by vaporization thereof effected through theabsorption of heat. As long as the temperature of the receptacle or bulb25 is substantially equal to the temperature of the liquefiedrefrigerant, nothing will happen. As soon, however, as the temperatureof the bulb 25 rises above the pressure temperature value, which valueis determined by the setting of back pressure valve It, then valve 1will be opened. This rise in temperature of the bulb 25 and thermallyresponsive fluid or vapor contained therein may be due to heat leak orwarm beverage flowing in the conduit III or both. If a heavy draught ofbeverage is taken off, a correspondingly heavy charge ofrefrigerant willbe introduced into the conduit or coil Ill. By proper design it ispossible to have a continuous flow of beverage and a continuous flow ofrefrigerant which is substantially completely evaporated before reachingbulb 25. The length of the conduit or coil ID from bulb 25 to fitting I5is in the nature of a drying coil to insure against frost back on. lineH under extreme conditions.

There is always a column of refrigerated beverage in the conduit or coill5 ready for instant use and this column will always remain cold.

In practice, the coil l0 may be severed at the bulb center and the partsbuilt up and soldered in place. I

In Fig. 2, bulb or receptacle 225 is shown on the outside of the coil.Within bulb 225, is a pipe M2 for refrigerant and within that is a pipe2 for beverage. This construction may be used where the beverage, asbeer, is stored in a refrigerated container and its temperature effecton bulb 225 is unnecessary. In such a case, bulb 225 is responsive onlyto the refrigerant medium directly. Indirectly of course, beverage inpipe 2, if warm, will cause refrigerant to vaporize in that region andwarm up the receptacle or bulb 225. Such a construction is cheaper thanthat disclosed in Fig. 1 and may advantageously be used in certaincases.

Fig. 3 shows outer pipe "2 for refrigerant enclosing bulb 325 as inFig. 1. Within bulb 325, however, are two pipes 3H! and 3H forbeverages. In this case, bulb 325 will respond to the warmest of the twobeverages. Along the length of. the entire coil, the temperature of thetwo beverages will be equalized so that if one is drawn heavily and theother lightly, the lightly drawn beverage column will tend to cool theother beverage column.

In Fig. 4 an outer pipe 430 is provided for one beverage. Within that isa refrigerant pipe 43L Inside of pipe 43l, is bulb 425 with one sidetouching pipe 43l. Within bulb 425 is a second beverage pipe 432. Byhaving bulb 425 in intimate contact along one side with 43l at point433, bulb 425 is made more responsive to conditions in the outerbeverage line 430. Conditions within beverage line 432 will affect bulb425 indirectly as in Fig. 2.

Fig. 5 is similar to Fig. 3 except that the two beverage pipes 5| II and5 are separate pipes instead of-one having a dividing wall. Otherwiserefrigerant line M2 and bulb 525 function as in Fig, 3.

It will further be noted that in all the flgures, the beverage conduitpresents a smooth and unbroken surface to the beverage flow. This isimportant for several reasons. Sincemany beverages are carbonated, thereis a tendency for gas to bubble out at sharp corners and projections andcause excessive foaming. Then in cleaning, a cleaning solution willfunction more effectively along a smooth surface.

The present invention provides a novel control for beverage coolingsystems and the like in which the cooling of the liquid is effected bydirect heat interchange from a volatile refrigerant to the liquid to becooled. The positioning of the bulb or receptacle 25 containing theexpansible fluid which governs the refrigerant inlet valve. so that theexpansible liquid is subjected predominantly to only the heating orcooling effects of the liquid to be cooled and the refrigerant, promotesa rapid response of the refrigerant inlet valve to a demand forrefrigerant. A body of the fluid which is responsive to temperaturechanges is thus housed in a receptacle having one wall positioned to betraversed by substantially all of the refrigerant flowing through therefrigerant passageway and having another wall to be traversed bysubstantially all of the liquid flowing through the liquid passageway.In this manner the body of thermally responsive fluid is subjectedsubstantially solely to the temperatures of the liquid being cooled andthe refrigerant to cool the liquid while the said liquid and refrigerantare flowing through their respective courses. Heating sources or coolingeifects outside of the cooling conduit do not directly influence theexpansible fluid in the thermostatic receptacle. Such effect as outsideheat or cold has on the control of the inlet valve is transmittedindirectly to the receptacle or bulb cooled liquid discharged. Onaccount of the extreme sensitiveness of the novel thermostatic devicefor controlling the admis ion of refrigerant to the cooling conduit theris avoidance of lag or delay in the supplying of fresh quantitles ofliquid refrigerant to cool a sudden or continued influx of warm liquid.

Other means of utilizing the principles of. the present invention arecontemplated, change being made in the particular details of procedureand construction set forth as required, it being understood that theembodiments shown are I given for purposes of explanation andillustration. 1

Having described the invention, what is claimed is: i

1. A liquid cooler comprising an outer conduit having an inlet end andan outlet end, pipe means arranged within said conduit and extendingthrough the same substantially from end to end and having outlet meansat the inlet end of said conduit, and a thermostatic control devicearranged within said conduit; said device comprising a sleevesubstantially enveloping a portion of said pipe means and cooperatingtherewith to form a fluidtight chamber having one wall subjected to thetemperature of fluid passing through said conduit, and a capillary tubecommunicating with the interior of said chamber and passing through saidconduit to the exterior thereof;

2. A liquid cooler, comprising a conduit having a plurality ofpassageways extending in parallelism therethrough, one of saidpassageways arranged to carry a refrigerant and another passagewayarranged to carry a liquid to be cooled, a pressure valve to regulatethe withdrawal of refrigerant from the conduit and maintain apredetermined pressure in the refrigerant passageway, an inlet valveassociated with the refrigerant passageway to regulate the admission ofrefrigerant thereto, and means responsive to temperature changes to openand close the inlet valve, said means including a receptacle positionedfor direct heat exchange with the passageways and intermediate the endsof the conduit, said receptacle being located within the said conduit inposition to be traversed by substantially all of the refrigerant flowingthrough said refrigerant passageway and by substantially all of theliquid flowing through the second mentioned passageway.

3. A liquid cooler, comprising a conduit having a plurality ofpassageways therethrough, one of the refrigerant passageway to regulatethe admis-, sion of refrigerant thereto, and means responsive totemperature changes to open and close the inlet valve, said meansincluding a receptacle positioned for direct heat exchangewith thepassageways and intermediate the ends of the conduit, said receptaclebeing located within the said conduit in position to be traversed bysubstanvtially all of the refrigerant flowing through said refrigerantpassageway and by substantially all of the liquid flowing through thesecond mentionedv passageway.

4. A liquid cooler, comprising a conduit having a plurality ofpassageways extending in parallelvalve associated with the refrigerantpassageway to regulate the admission of refrigerant thereto, and meansresponsive to temperature changes to open and close the inlet valve,said means including a receptacle positioned for direct heat exchangewith the passageways and intermediate the ends of the conduit, saidreceptacle being 10- cated withinv the said conduit" in position to betraversed by substantially, all of the refrigerant flowing through saidrefrigerant passageway and by substantially all of the liquid flowingthrough the second mentioned passageway.

5. A liquid cooler, comprising a conduit and one or more parallel pipespassing through the interior of said conduit and cooperating therewithto form passageways extending longitudinally through the conduit, aninlet valve to regulate the admission of liquid refrigerant to one ofthe pas sageways, means to control the operation of said valve, saidmeans including a receptacle located within said conduit in position tobe subjected directely to temperature changes in each of the passagewaysat a region intermediate the ends of the conduit, and a pressure valveto regulate the withdrawal of refrigerant from the refrigerantpassageway, said pressure valve arranged to permit the flow ofrefrigerant out. of the refrigerant passageway when the pressure thereinexceeds a predetermined value and to prevent such flow when the pressuretherein is less than a predetermined Value 6. A liquid cooler comprisinga plurality of passageways extending in substantially side by sideparallel relation,'one of said passageways having an inlet and an outletand arranged to carry a volatile refrigerant, another of saidpassageways arranged to carry a liquid, means for supplying refrigerantto the refrigerant passageway, a pressure valve to regulate thewithdrawal of refrigerant from the refrigerant passageway and maintain asubstantially uniform predetermined pressure therein, an inlet valveassociated with the inlet end of the refrigerant passageway to regulatethe admission of liquid refrigerant, and means responsive to temperaturechanges to open and close the inlet valve, said means including areceptacle for an expanslble fluid positioned between the passagewaysand having one wall in common with the refrigerant passageway to betraversed by substantially all of the refrigerant flowing through therefrigerant passageway, and

another wall in common with the liquid passageway to be traversed bysubstantially all the liquid flowing through the said liquid passageway,and

the receptacle arranged to be alternately subjected to substantiallypredominantly liquid re-' frigerant and to substantially predominantlygaseous refrigerant as the effective level of liquid refrigerantadvances and recedes in the refrigerant passageway.

7. The method of cooling a liquid which comprises passing the liquidover a course traversing one side of a body of fluid responsive totemperature changes, passing a volatile refrigerant over a courseparalleling the; course of the liquid to be cooled and in directheat-exchanging relation therewith and over another side of the saidbody of fluid, maintaining a substantially constant pressure on therefrigerant in the refrigerant course, subjecting said body of fluidsolely to the temperatures of said liquid and said refrigerant in saidcourses, and controlling the admission of refrigerant to the refrigerantcourse solely in response to changes in temperature of said body offluid.

8. The method of cooling a liquid which comprises passing the liquidover a course traversing one side of a body of fluid responsive totemperature changes, passing a volatile refrigerant first a refrigerantcourse solelyin response .to changes in temperature of said body offluid. 8. The method of cooling a liquid which comprises passing theliquid over a-course which flrst traverses a body of fluid responsive totemperature changes and then parallels a refrigerant course, passing avolatile refrigerant over a cours which first parallels the liquidcourse in heatexchanging relation therewith and then traverses anotherside of said body of fluid, maintaining a substantially constantpressure on the refrigerant in the refrigerant course throughoutsubstantially the entire length thereof, subjecting said body of fluidsolely to the temperatures of said liquid and said refrigerant in saidcourses, and controlling the admission of refrigerant to the refrigerantcourse solely in response to changes in temperature of said body offluid.

10. The method of cooling a liquid which comprises passing the liquidover a generally descending course which first traverses a body of fluidresponsive to temperature changes and then parallels a refrigerantcourse, passing a. volatile refrigerant in a generally ascendingdirection over a course which flrst parallels the said liquid course inheat-exchanging relation therewith and then traverses another side ofthe said body of fluid, maintaining a substantially constant pressure onthe refrigerant in the refrigerant course throughout substantially theentire length thereof, subjecting said body of fluid solely to thetemperatures of said liquid and said refrigerant in said courses, andcontrolling the admission of refrigerant to the refrigerant coursesolely in response to changes in temperature of said body of fluid.

DEWEY H. DOLISON.

